ctDNA Guidance for Clinicians for Patients with Advanced Lung Cancer

Update

ctDNA Guidance for Clinicians for Patients with Advanced Lung Cancer

Liquid biopsy testing is now available for eligible patients with suspected lung cancer across the country. To assist with the delivery of this service, we have developed the below guide for clinical teams interpreting results of a lung ctDNA test.

March 5, 2026

Determine which category the blood result falls into:

1. Informative result: Abnormality suggests first-line targeted treatment available (GREEN)

2. Informative result but no first-line targeted treatment available (ORANGE) (note second-line targeted or clinical trial treatments might be available such as KRAS G12C, NTRK or ERBB2)

3. Result not informative to make initial treatment decision (RED). This may be because:

There is insufficient circulating tumour DNA in the sample or
There is not an oncogenic abnormality in one of the key genes below to enable a confident treatment decision on the basis of the ctDNA alone at this time. This information may still be useful in guiding the subsequent care of the patient.

The determination of which category the result can be falls into can be made by any suitably trained person including a respiratory physician or oncologist; if there is any doubt as to which category the result falls into it should be discussed with your GMS.

Action to be taken

1. Informative result: Abnormality suggests first-line targeted treatment available (GREEN)

Start targeted treatment immediately if radiology in keeping with stage 3 not suitable for radical treatment or stage 4 lung cancer. This is in line with NHS guidance and Blueteq criteria

2. Informative result but no first-line targeted treatment available (ORANGE)

Once histological confirmation of NSCLC is in place start appropriate systemic treatment; there is no requirement to await tumour molecular profiling.

3. Result not informative to make initial treatment decision (RED)

Await histological confirmation and tumour molecular profiling if appropriate before starting treatment (as per previous practice).

The table below can be used to guide clinical management based on pathogenic abnormalities in the genes below and the reported percentage in the blood (VAF or Variant Allele Frequence).